Conventionally, some of vehicle rear seats are provided with a tilt down mechanism that permits to place seat backs of the seats not in use to a folded condition in which the seat backs are folded down forwardly toward the seat cushions. Further, some of the vehicle rear seats are provided with a walk-in mechanism that permits the entire seats to slide to a retracted position at a front side of the vehicle while placing the seat backs to a forwardly inclined condition in which the seat backs are tilted down forwardly toward the seat cushions The former, i.e., the tilt-down mechanism, places the seat in the folded condition when, for example, the seat is not in use. As a result, a back surface of the seat back functions as a floor surface, thereby increasing a baggage space in a rear side of a vehicle. The latter, i.e., the walk-in mechanism, functions to increase passenger space when, for example, a passenger gets in and out of a seat that is positioned behind the rear seat via a door beside the rear seat.
In such cases, the seat is provided with a tilt down operation lever and a walk-in operation lever in order to operate the respective mechanisms. It is considered that the above-mentioned operation levers are preferably collectively positioned at a door-facing shoulder portion of the seat back. This is because when the operation levers are positioned as described above, it is possible to easily operate the tilt down mechanism and the walk-in mechanism from a door-facing side or from behind the seat.
An art with regard to the arrangement structure of the above-mentioned operation levers in the seat is disclosed, for example, in Japanese Laid-Open Patent Publication No. 7-52697. In this disclosure, a knob corresponding to the tilt down operation lever is positioned at a shoulder portion of a back surface (a surface facing backward of a vehicle) of the seat back. When the knob is lifted up so as to release a locked condition of the seat back, the seat back can be folded down forwardly toward a seat cushion, so as to be placed to a folded condition.